Settling basins typically use sedimentation to remove suspended solids from fluid using gravity. Settling basins may be formed of a structure such as concrete, or an earthen structure, for example a settling pond.
Settling basins may collect inflowing fluid such as storm water or waste water through an inlet. Inflowing fluid may carry suspended solid particles that may include dirt, sand, litter, or other waste. As the inflowing fluid enters the basin, particles in the fluid are separated by gravity and particles settle to the bottom of the basin to form sediment. The fluid is retained in the basin for a settling time that allows the desired particle size to be separated. Smaller particles may require longer settling time or larger volume basins, as smaller particles have a smaller settling velocity, defined as the terminal velocity reached by a particle as it falls through a fluid.
Following settling, water may outflow from the settling basin at an outlet or overflow points.
Settling within the basin may be affected by turbulence in the water. Turbulence may be caused, for example, by wind, geometry of the basin, inlet design and outlet or overflow design.
High flow rate or fast-flowing inflowing fluid may agitate settled sediment in conventional settling basins, for example, in periods of increased flow rate or volume of inflowing fluid, a storm event or periods of heavy rainfall intensity.
Using traditional maintenance methods, an entire settling basin may be drained to allow sediment that has settled on the bottom of the basin to be removed manually or using a machine such as a mechanical loader or crane, or a vacuum truck.
Accordingly, there is a need for improved collection and removal of sediment collected from inflowing fluid.